Mercenary Fighters

I do not quite understand. Can you give me a basic answer that isn't confusing lol. As a short and easy to understand the meaning of each word and the difference [Thanks big points]

A freedom fighter fights for an ideal. The money is secondary.
A mercenary fighting for the money. The ideal is secondary.

Between the professional soldier. He fought for his country (or enemies that his country wants to fight him). It does for some of the money, in part to an ideal, and partly because of legal obligations.

A Taliban or Hamas Fighter is a fighter for freedom (a freedom fighter to one is a terrorist to others)
An American soldier is a professional soldier
An employee of Blackwater is a mercenary

freedom fighter fights for free

costs mercenaries you

A freedom fighter fights for a cause he believes in. Personally
A mercenary is a gun "for hire", he fights for him who always pays the most money and leaves
if and when the interruption of earnings. It does not necessarilly believe in the cause he fights.

freedom fighters fight for freedom, because they must, like Spartacus
Mercenary struggle for money as John Hawkwood